| abstract |
The walls of through holes and vias of a substrate with a dielectric material are electrolessly plated with copper using a tin-free ion silver catalyst. First, a conductive polymer is formed on the substrate by treating the substrate with a permanganate solution containing a complex anion, and then a monomer, oligomer, or conductive polymer is applied to the substrate to form a conductive polymer. A conductive polymer coating is formed on the dielectric of the substrate and on the walls of the vias and vias of the substrate. A tin-free ionic silver catalyst is then applied to the treated substrate. Optionally, the tin-free silver catalyst may include a ligand reagent to form a coordination entity with the silver ion of the tin-free catalyst. The silver ions of the tin-free catalyst are reduced by a conductive polymer, and then an electroless metal copper bath is applied to the processed substrate to align the dielectric of the substrate and the vias and vias. The walls are copper plated. |